Mystery White Spot Beckons in Dawn Probe’s View of Ceres

The latest views of the dwarf planet Ceres from NASA's Dawn spacecraft reveal hints of craters — and a relatively bright spot that's been a mystery for more than a decade. The black-and-white snapshots were taken on Jan. 13 from a distance of 238,000 miles (383,000 kilometers) and released on Monday. It's still a fuzzy view, with 80 percent of the resolution of the Hubble Space Telescope's images of Ceres from 2003-2004, but the picture will get much sharper as Dawn approaches for a rendezvous in March.

The white spot showed up in Hubble's earlier images. Although scientists can't yet say exactly what it is, the best hypothesis is that it's a frozen pool of water ice at the bottom of a crater, clear enough to reflect sunlight. Scientists have detected puffs of water vapor emanating from Ceres that could hint at subsurface reservoirs of liquid water. That naturally leads to speculation about life on Ceres, which is the biggest object in the main asteroid belt as well as the smallest known dwarf planet. Will Ceres' mysteries be solved in March? Stay tuned.



— Alan Boyle